Extruder



July 2%, 1954 R. o. SCOFIELD EXTRUDER 9 Sheets-Sheet 1 Filed July 21, 1950 R. O. SCOFIELD EXTRUDER 9 Sheets-Sheet 2 Filed July 21, 1950 Jufly 20, 1954 R0. SCOFIELD EXTRUDER 9 Sheets-Sheet 3 Filed July 21, 1950 July 20, 1954 R. o. SCOFIELD 2,683,895

EXTRUDER Filed July 21, 1950 9 Sheets-Sheet 4 July 20, 1954 R. o. SCOFIELD EXTRUDER 9 Sheets-Sheet 5 Filed July 21 1950 July 20, 1954 R. o. SCOFIELD EXTRUDER 9 Sheets-Sheet 8 Filed July 21 1950 20, 1954 R. o. SCOFIELD 2,633,895

EXTRUDER Filed July 21. 1950 s Sheets-Sheet 9 Patented July 20, 1954 UNITED STATES PATENT OFFICE EXTRUDER Robert 0. Scofield, Warren, Ohio, assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware 6 Claims.

This invention relates to the manufacture of insulated wire comprising a metal core and a sheath of plastic material formed around the wire by an extruder.

The object of the invention is to provide an extruding machine having means for preparing the material for use by the extruder head. This object is accomplished by a. plurality of heated, material kneading devices located in series relation between a feed screw and the extruder head.

A further object of the invention is to adapt the machine for the preparation of different kinds of material. Therefore the machine provides for adjusting the speed of the kneading devices relative to the speed of the feed screw and for changing the speed relation of the kneading devices.

A further object is to facilitate the cleaning of the machine. Therefore this machine provides a unitary structure containing the kneading devices which can be easily removed from its housing and which can be easily disassembled.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Figs. 1 and 2 constitute a plan View of the machine.

Figs. 3 and 4 constitute an enlarged sectional view on line 3-3 of Figs. 1 and 2.

Fig. 5 on the same sheet with Fig. 3, is a fragmentary sectional view on line 5-5 of Fig. 3.

Fig. 6 is a sectional view on line 66 of Fig. 3.

Fig. 7 is an enlargement of that portion within circle I of Fig. 3.

Fig. 8 is a fragmentary side elevation of the machine in the direction of the arrows 8 of Figs. 1 and 2.

Fig. 9 is an end view in the direction of arrow 9 of Fig. 1.

Fig. 10 is a fragmentary sectional view on line I0I0 of Fig. 9.

Fig. 11 is a view of a lubricating oil distributing manifold.

Fig. 12 is a fragmentary view in the direction of arrow [2 of Fig. 8.

Fig. 13 is an enlarged sectional view on lines I3--I3 of Figs. 2, 14 and 15.

Figs. 14 and 15 are sectional views taken, respectively, on lines I i-I4 and I5|5 of Fig. 13.

Fig. 16 is a side view of an assembly of various housing.

Fig. 17 is a continuation of Fig. 3 to show the extruder head.

2 Fig. 18 is an enlarged sectional view on line Iii-I8 of Fig. 17.

Referring to Fig. 9, a base plate I0 supports a frame II which supports an electric motor M which drives a shaft 23 (Fig. 1) connected by a coupling 24 with a shaft 25 connected with a gear 26 connected by a chain 2'! (Fig. 1) with a gear 28 which drives an oil pump P which pumps oil from a tank I2 which supports it and forces oil through pipes 29 and 30 to an hydraulic motor H (Figs. 1 and 2) connected by an oil return pipe 32 with tank I2. Pump P is of the piston type and the displacement of the piston can be varied by adjusting a mechanism in cam 33 (Fig. 9) by turning a handwheel 34 in order to vary the relation of the speed of the hydraulic motor H relative to the speed of electric motor M which drives the pump P. A guard 31 encloses the chain 27 and gears 26 and 28.

Referring to Figs. 8 and 16, a base frame I3 supports a bracket I4 and a feed screw housing I6. Bracket I4 supports a kneader housing I I attached to housing I6. Housing I6 supports a shaft coupling housing I5 and a spacer plate I5a. A transmission housing comprising members I8 and I9 (Fig. 8) is supported by base I3 and supports a plate 52 and one end of the housing I5.

The housing I8, I9 is part of a feed-screw power transmission sub-assembly including shaft 25 (Fig. 10), gear 26, shaft bearings 40, bearing sleeves 4| and bearing retainer caps 42.

Shaft 25 is connected with gears 45 which mesh with gears 46 (Figs. 9 and 1) connected with a shaft 4'! supported by housing I8, I9 in a manner similar to that by which said housing supports shaft 25. Gears 46 (Fig. 1) mesh with gears 48 which, as shown in Fig. 4, is connected by a pin 49 with a shaft 50 journaled in bearings 5| supported by a plate 52 attached to housing I8, I9 as shown in Figs. 1 and 4. Shaft 50 has splines 53 received by internal splines of a coupling 54 journaled in bearings 55 and 56 mounted, respectively, in the housing l5 and in a plate I 5a. Screws I5b attach housing I5 and the adjacent plate 52 to the housing I8, I9. Screws 51 attach housing I6 and plate I511 to housing I5. Housing I5, coupling shaft 54, bearings 55 and 56, plate I51; and seal rings 58 provide a shaft coupling sub-assembly unit.

Coupling 54 is connected by a key 60 with a shaft 6| which provides a feed screw 62 within a hard metal sleeve 63 located within housing I6 and extending within a sleeve 64 (Fig. 3) within the housing I'I. Housing I6, shaft BI and tube 63 provide the feed screw sub-assembly. Housing I6 provides a material receiving hopper I05 (Fig. 4) and passages I66 for receiving a heating medium such as steam.

The sleeve 64 (Fig. 3) has a recess which receives a screen 66 and a perforated plate 51 retained by a cylinder 19 received by a cylindrical bore H in a housing I1 and retained therein by a nut 12. Cylinder 16 provides a ocket 13 which receive meshing gears 14 and 15 of a kneader A. The material to be worked is forced by the screw 62 through the screen 66 and perforated plate 61 and through distributing passages 16 to the kneader A from which the material is discharged through duct 11 to a funnel shaped nut 18 (Fig. '1) which retains a block 19 having a metering orifice 86 within a cylinder SI located in a cross bore 82 in cylinder 16. Cylinder BI is retained by nuts 83 screwed into cylinder 19. After the material passes the orifice 89, it is distributed again through ducts 84 provided by a disc 85 received by a recess in cylinder 16 and retained therein by cylinder 6|. Cylinder BI has a slot 66 to permit removal of cylinder BI from cylinder 16 (after cylinder 16 has been withdrawn from housing I9) while disc 85 remains assembled with the cylinder 16. After removal of cylinder 8| from cylinder 16, the disc 85 can be removed. Disc 65 locates the cylinder 8I so that block 19 is aligned with duct 11.

The material is forced through the ducts 84 of disc 85 into a pocket 89 which receives meshing gears 96 and 9| of kneader B. From kneader B, the work material passes through the flaring opening 92 to an extruder head 2I6 (Fig. 2) clamped to housing I1 by a bar 2 engaged by nuts 93a threaded on screws 93. is provided with steam passages I6I which are connected with a source of steam by pipes, such as I62 (Fig. 3) threaded into plates I63 attached to the frame or housing. The material to be kneaded is passed into the housing I6 through the hopper I65 (Fig. 4) and the screw 62 picks the material up and forces it through the tube 63 to the kneaders A and B which pass it to the extruder head 2I6. The housing I! and parts supported thereby constitute a kneader sub-assembly which can be removed from the machine without removing other sub-assemblies as will be explained later.

The hydraulic motor H (Figs. 2 and 8) which is supported by a bracket 22 supported by frame I3 drives a shaft III which drives mechanism contained in a housing 26 which together with said mechanism constitutes a kneader power transmission sub-assembly unit which is removable from the machine without removing other sub-assemblies.

Referring to Fig. 13, shaft III has splines I26 by which it is connected with a tubular shaft I2I journaled in bearings I22 and I23 mounted respectively in housing 26 and a housing cover I24. Shaft I2I provides a gear I25 meshing with a gear I26 connected with a shaft I21 journaled in bearings I28 and I29 mounted in housing 26 and in a bearing I30 mounted in cover I24. Shaft I21 provides a worm I31 which meshes with a worm gear I32 having a hub I33 splinedly connected with a shaft I34 (Fig. 15). Shaft I34 is journaled in bearings I35 and I36 mounted in housing 26 and a ring I31 to which a ring I38 is attached. In the ring plug I39 which receives a thrust bearing I46 engageable with a shoulder I4I of the shaft I34. Shaft I34 has a square socket I42 for receiving the square end of a shaft with which the gear 14 (Fig. 3) is integral.

The housing I1 I36 there is screwed a Shaft I21 (Fig. 13) is connected with a gear I56 which meshes with a gear I5I connected with a shaft I52 journaled in bearings I53 mounted in housing 26. Shaft I52 provides a worm I54 meshing with a worm gear I55 which, as shown in Fig. 14, is integral with a tubular shaft I56 journaled in bearings I51 and I58 mounted, respectively, in housing 26 and a ring I59 to which a ring I66 is attached. A plug I6I screwed into ring I66 supports a thrust bearing I62 for engaging a shoulder I63 of a shaft I64 splinedly connected with shaft I56 and extending through a bearing bushing I65 mounted in housing I1 and providing a square socket I66 which receives the square end of a shaft I61 integral with gear 96 (Fig. 3). Gear 96 and gear 9I meshing therewith are journaled in bearing plates 92 and 93 which close the end of pocket 89 (Fig. 3) and which are retained by nuts 94 and 95 respectively. The construction providing for the support of gears 14 and 15 of kneader A, for the closure of the pocket 13 and for the connection of gear 14 with shaft I34 of Fig. 15 is identical with that just described for supporting closing and driving gears and SI of kneader B.

Gears I59 and I5I (Fig. 13) are housed in a chamber I10 of housing 26 which is closed by a cover I1 I. To change the speed relation between kneaders A and B, the cover I1I is removed and gears I56 and I5I are replaced by meshing gears of other diameters.

The cylinder 16 (Fig. 3) is located within the bore H of housing I1 by a key I12 attached to cylinder 16 and received by a groove I13 in housing I1 and by a dowel pin 65 attached to sleeve 64 and received by a hole I15 in the left end of cylinder 16.

The cylinder 16 and parts supported thereby can be removed from the bore "H of housing 65 as a unit. In preparation for such removal, the plug I39 (Fig. 15) and the plug ISI (Fig. 14) are removed and shafts I34 and I64 are retracted from housing I1. The nut 12 (Fig. 3) is removed. The worm or feed screw 62 is rotated in normal direction to cause any material therein to be moved toward the right, thereby causing it to push upon the screen 65, plate 61 and cylinder 16 so that the right end of cylinder 16 will project out beyond the right end of housing I1 from which the extruder head 2 I 6 had previously been removed. Thus the screen 66 and plate 61 are removed for cleaning and the parts assembled with cylinder 19 can be removed. After removing the nuts 94 and (Fig. 14), the bearing plates 92 and 93 and the gears 96 and SI can be disassembled from the cylinder 16. In a similar manner, the gears 14 and 15 and supporting plates are removed. After removing the nut 83 which appears lower as shown in Fig. 3, the cylinder 8| and parts assembled therewith can be removed. After such removal, the disc 85 can be removed. By unscrewing the nut 19 (Fig. '7), the block 19 providing the metering orifice 86, can be removed. Thus all of the parts assembled with cylinder 16 as a unitary structure can be disassembled readily for purpose of cleaning or replacement of worn parts.

The retraction of shaft I34 (Fig. 15) and shaft I64 (Fig. 14) permits removal of the kneader power transmission sub-assembly unit from the machine without requiring removal of the kneader sub-assembly unit or the hydraulic motor I-I. Housing 26 is detached from housing I1 (Fig. 14) by removing screws 26a; and housing 2.9 is

detached from bracket 2! by removing screws Then the kneader power transmission sub-assembly unit is removed from the machine by moving housing 20 right (Fig. 8) in a direction parallel to the axis of shaft 1 l l.

Oil for lubricating the mechanism in housing 20 is placed in the bracket 2! which is hollow (Fig. 12). A pump p driven by shaft l2! (Fig. 13) withdraws oil from bracket 2i and forces it to manifold 200 (Fig. 11) and distribution pipes 2E feed oil to said mechanism. Excess oil returns to bracket 2| through a drain duct 292 and a drain pipe 203.

The speed at which the material is moved by the screw 62 depends upon the speed of the screw and the resistance to movement of the material through the screen 66 and plate El and also the resistance to movement of the material through ducts 16 (Fig. 3). Obviously resistance must be present in order to effect feeding of the material by the screw 62 since there must be slippage between the screw and material in order to effect a feeding operation. The extent to which the material is worked by a kneader A depends upon its speed of rotation and the resistance to flow through the metering orifice 8% which has a diameter such that the particular material being handled will receive the proper amount of kneading action. In order that the material will be effectively kneaded by the kneader B, there is resistance to movement of the material through the duct 92 since a strainer plate H2 and the extruder head 2H3 (Figs. 17 and 18) attached to housing I! offer resistance to flow of material as it is extruded around a wire. For some types of material it may be advantageous to rotate gears 90 and M of kneader B at a rate less than the rate of rotation of gears it and E5 of kneader A, so that the rate of discharge of material into passage 90 will be somewhat less than the rate at which the material is received into the gear pocket 89.

The machine can be readily adapted for working various kinds of materials by adjusting the speed of the hydraulic motor H so that the relation of kneader speed to feed screw speed can be varied, by adjusting the speed ratio between kneaders A and B and by the substitution of a disc 19 having orifices of different diameters.

The extruder head 218 which, together with the perforated strainer plate 2l2 are clamped to the housing 1?, may be any suitable type such as illustrated in Figs. 17 and 18. As shown, the head Zill comprises a block 2| 3 which supports a bushing 2| 4 which supports a guider holder 215 which supports a wire guider 216 having a central bore 2 lfia through which a wire passes to a guider tip 2 if supported by the guider 216 and a bridge 2H8 supported by the bushing 2M. The wire coating material is forced through openings 2 IS in bridge 2 I8 and through a die 22f! supported by a die holder 22! located by bushing 2E5 in alignment with guider tip 2H. Plugs 222 and 223 threaded into block 2L3 retain extruder head parts in the block 2i3. Screws 22d secure to bushing 2M a key 225 received by a groove 225 in block M3 to prevent turning of the bushing 2M so that the side opening 214a of bushing 2M remains aligned with the funnel-like opening 2 [3a of block 2|3. The block M3 is provided with steam receiving passages 227.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. An extruder comprising an extruder head which forms a sheath of the material around a wire and apparatus for preparing material for use by the head, said apparatus comprising a feed screw, power means for rotating the screw, two kneading devices in series with the screw and extruder head, each device comprising a pair of meshing gears, ducts distributing material discharged by the screw to the first of the devices, a duct providing a restriction to passage of material from the first kneading device, ducts distributing material passing through the restricted duct to the second kneading device, a duct through which material passes from the second kneading device to the extruder head which limits the rate of material flow through the last duct, a frame having a recess extending from the feed screw to an open end of the frame which is adapted to receive an extruder, a housing received by the frame and enclosing the ducts and providing gear receiving recesses, members received within the housing for closing the ends of the recesses and providing bearings for the gears, detachable means within the housing for securing the members in position, disconnectible means for transmitting rotary motion from the power means to the gears and comprising two longitudinally movable power shafts providing, respectively, couplings with gears of the two kneading devices, said shafts being extendable into the frame recess to effect coupling with the gears and retractable from the frame recess to effect uncoupling, the housing and parts supported thereby being removable as a unit from the frame recess when the shafts are retracted and the extruder head is detached from the frame, and detachable means for securing the housing within the frame recess.

2. An extruder comprising an extruder head which forms a sheath of the material around a wire and apparatus for preparing material for use by the head, said apparatus comprising a feed screw, power means for rotating the screw, two kneading devices in series with the screw and extruder head, each device comprising a pair of meshing gears, ducts distributing material discharged by the screw to the first of the devices, a duct providing a restriction to passage of material from the first kneading device, ducts distributing material passing through the restricted duct to the second kneading device, a duct through which material passes from the second kneading device to the extruder head which limits rate of material flow through the last duct, a frame having a recess extending from the feed screw to an open end of the frame which is adapted to receive the extruder head, a housing received by the frame providing gear receiving recesses, members received within the housing for closing the ends of the recesses and providing bearings for the gears, detachable means within the housing for securing the members in position, said housing providing, between the gear receiving recesses, a third recess extending cross-wise of the frame recess, a body in said third recess, detachable means for retaining the body in the third recess, a passage provided by the body for connecting the gear receiving recesses, a block located in said passage and providing the restricted duct, a member providing the distributing ducts to the second kneading device and retained in position by said body and locating the body in the third recess, said housing providing the distributing ducts leading to the first kneading device and the duct leading from the second kneading device, means for transmitting rotary motion from the power means to the gears and comprising two longitudinally movable power shafts providing, respectively, couplings with gears of the two kneading devices, said shafts being extendable into the frame recess to effect coupling with the gears and retractable from the frame recess to effect uncoupling, the housing and parts supported thereby being removable as a unit from the frame recess when the shafts are retracted and the extruder head is detached from the frame, and detachable means for securing the housing within the frame recess.

3. In apparatus for preparing material for use by an extruder head, the combination comprising a material receiving hopper, a screw for feeding material from the hopper, rotary kneading means receiving material from the screw and passing it to an extruder, an electric motor, a variable displacement pump for pressurizing hydraulic fluid, mechanism for connecting the motor with the screw and the pump, a pressure fluid operated motor connected with the pump and operat ng a shaft and mechanism connecting the fluid motor shaft with the kneading means.

4. In apparatus for preparing material for use by an extruder head, the combination comprising a frame, a rotary kneader enclosed thereby, said kneader having a rotary shaft providing a coupling member within the frame, a motor having a shaft for driving the shaft of the kneader, said motor shaft being located at a right angle to the kneader shaft, a housing attached to the frame, a first shaft within the housing and having a coupling connection with the motor shaft which is disconnected by moving the housing in a direction axially of the motor shaft, a second shaft supported by the housing in alignment with the kneader and mounted for axial movement and providing a coupling engaged by the kneader shaft coupling when said second shaft is advanced into the frame and gearing supported by the housing for connecting said first and second shafts, said housing and the shafts and mechanism supported thereby being removable as a unit from the frame after the housing has been disconnected from the frame and the second shaft has been retracted from the frame.

5. In apparatus for preparing material for use by an extruder head, the combination comprising a base frame, a feed screw sub-assembly supported by the base frame and comprising a housing, a material receiving hopper provided by the housing, a tube in the housing receiving material from the hopper, a shaft extending exterior to the housing and located within the tube and providing therein a feed screw; a kneader subassembly and comprising a housing, supported by the frame and attached to the feed screw subassembly housing, a rotary kneader in the kneader housing and having a shaft providing a shaft coupling member; a kneader driving motor supported by the base frame having a shaft; a kneader transmission sub-assembly comprising a housing supported by the frame and attached to the kneader housing, a shaft providing a coupling with the kneader motor shaft, a shaft providing a coupling with the kneader shaft and mechanism connecting the shafts supported by the kneader transmission housing; a screw shaft coup-ling sub-assembly comprising a housing attached to the screw shaft housing and a shaft coupling rotatably supported thereby and receiving and providing a coupling with the screw shaft; and a power transmission sub-assembly and comprising a housing supported by the base frame and attached to the housing of the screw coupling, a power input shaft having a coupling for connection with the shaft of a driving motor, a power output shaft having a spline connection with the coupling in the housing of the screw shaft coupling sub-assembly and gearing connecting the shafts supported by the housing of the power transmission sub-assembly.

6. An extruder comprising an extruder head which forms a sheath of the material around a wire, and apparatus for preparing material for use by the head, said apparatus comprising a feed screw, power means for rotating the screw, two rotary, material kneading devices in series with the screw and the extruder head, variable speed power means for operating the devices, means for changing the speed of operation of said kneading devices relative to the speed of rotation of the feed screw, and means for heating the screw and devices.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,302,484 Stratton et al Apr. 29, 1919 1,595,470 Johnson Aug. 10, 1926 

